1. Field of the Invention
The present invention relates to an image forming apparatus such as a printer, a facsimile machine or a copying machine and to a paper feed device for supplying paper to the image forming apparatus.
2. Description of the Related Art
As a paper feed device for supplying paper to an image forming apparatus such as a printer, a facsimile machine or a copying machine, there has been known a device having a configuration in which a setting plate having sheets of paper stacked thereon is suspended with a wire rope or the like to allow a large amount of sheets of paper to be stored and in which the wire rope is wound by means of a motor or the like to elevate the setting plate to control the uppermost surface of the sheets of paper at a predetermined elevation for feeding sheets of paper.
In this type paper feed device, since a paper feed unit such as a pickup roller abuts on the uppermost surface of the sheets of paper placed on the setting plate, the setting plate elevated by the motor or the like needs to be once moved down in order to supply sheets of paper.
In the related-art paper feed device, therefore, the setting plate is elevatably provided in a paper cassette, which can be attached/detached to/from the image forming apparatus. When the paper cassette is removed from the image forming apparatus, the setting plate in the paper cassette is separated from a driving shaft of a motor in the image forming apparatus so that the setting plate can go down because of its own weight (JP-A-Hei. 8-217266).